Flat package bridge rectifier



Feb. 28, 1967 B. BERNSTEIN FLAT PACKAGE BRIDGE RECTIFIER Filed Oct. 25,1965 INVENTOR.

BERNARD BERNSTEIN m'ronusvs 3,307,077 FLAT PACKAGE BRIDGE RECTIFIERBernard Bernstein, 3900 Kings Highway, Brooklyn, N.Y. 11234 Filed Oct.23, 1965, Ser. No. 502,958 9 Claims. (Cl. 317-99) This invention relatesto rectifiers, and more tifiers.

The general object of the invention is to improve such rectifiers. Amore particular object is to provide such a rectifier in the form of afiat package which is sturdy and inexpensive, both for parts and forassembly labor. Another object is to provide a rectifier package whichis unusually compact in size, and which is made up of a minimum numberof parts. To accomplish the foregoing general objects, and other morespecific objects which will hereinafter appear, my invention resides inthe bridge rectifier elements and their relation one to another as arehereinafter more particularly described in the following specification.The specification is accompanied by a drawing in which:

FIG. 1 is a perspective view showing parts of the rectifier in spacedrelation;

FIG. 2 is a plan view nal strips and cover;

FIG. 3 is a similar view after adding the top terminal strips, andbefore adding the cover;

FIG. 4 is a vertical section taken on the line 44 of FIG. 3 after addingthe cover;

FIGS. 5 and 6 are plan and edge views respectively of a modification;and

FIG. 7 is a diagram schematically explaining the electrical relation ofthe rectifier stacks.

Referring to FIG. 2 of the drawing, the rectifier comprises four stacksof rectifier cells 12, 14, 16 and 18 arranged in a square. There arefour elongated terminal strips, one of which is indicated 'at 20 inFIG. 1. Each has a soldering lug (64 in FIG. 1) for external connection.One pair of two such terminal strips are arranged collaterally beneath24 in FIGS. 2 and 4. nal strips is disposed rectifiers, especiallyselenium particularly to closed end bridge recprior to addition of thetop termiabove the stacks, and transversely of the first pair, as isindicated at 26 and 20 in FIG. 3. There is also a means, in this case acover 30, for compressing the terminals and stacks for good electricalcontact. The assembly then has four soldering lugs for externalconnection to the corners of the closed end bridge of rectifiers formedwithin the package.

The terminal strips are preferably made of resilient metal, and areconcavo convex, so that when loaded they resilient pressure to thestacks of The terminal strips may be made of hard cold rolled steel, orthey may be made of spring steel, and in either case they are preferablytinned or coated with some other suitable corrosion resistant metal.

The cells and terminal strips are housed in a molded insulating casehaving a bottom 32 (FIG. 1) and four edge walls 34, 36, 38 and 40, atleast some of which have vertical slots which are open at the top. Therecould be a single slot in each of the four walls, making four slots inall, for the four soldering lugs, but it is considered United StatesPatent 0 3,307,077 Patented Feb. 28, 1967 more convenient for eventualwiring in a circuit to provide two slots on each of two adjacent walls,as shown in FIG. 1. The wall 34 has two full depth slots 42 and 44,while the adjacent wall 36 has two short slots 46 and 48.

There is a first partition 50 which extends from the slotted wall 34 tothe opposite wall 38, and a second partition which extends from thesecond slotted wall 36 to the full depth in the region between thepartition 50 and each of the sidewalls 36 and 40. Differently expressed,it is made up of short pieces 52, 54, 56 and 58.

The terminal strips (20 in FIG. 1) are notched at the side edges asshown at 62, to receive the parts 52, 54 or the parts 56, 58. Thesoldering lug 64 at one end of the terminal strip is dimensioned to passthrough slot 42 or 44. Thus two of the terminal strips may be laid onthe bottom 32 of the case, one on each side of partition 50, with thelugs projecting through the slots 42 and 44.

The rectifier stacks are built up of superposed selenium cells. One suchcell is indicated at 66 in FIG. 1. As here illustrated each stackcomprises four cells, but the number used may vary. The cells may beconventional selenium cells having a suitable base metal, typicallyaluminum. The selenium is preferably vacuum deposited on the aluminum.In simplest form the cells are square, as here illustrated. The cellsare dimensioned to be received transverse partition 5258.

The top terminal strips 26 and 20 overlie the first partition 50, asshown in FIGS. 3 and 4. They have soldering lugs 60 and 64 which passthrough the short slots 46 and 48 previously referred to. In preferredform the first partition 50 is interrupted, somewhat like the secondpartition, but for only a slight depth, as shown at 68 in FIG. 1, thisdepth being sufiicient to receive the top terminal strips, and for thatreason the top strips, like the bottom strips, are preferably notched atthe sides 'as shown in FIG. 1.

ing a depending locating stud 74 at the center, and having four holes 76near its periphery dimensioned to frictionally receive the four studs72. The cover may be molded of an insulaing material, preferably thesame material as the case.

This material may be a plastics material having suitable characteristicsin respect to electrical insulation and moldability. Nylon is asatisfactory material, but I prefer to use a polycarbonate plastic suchas Lexan made by General Electric Company.

In FIG. 4 the bottom terminal strips 22 and 24 are shown disposed withthe convex face upward, but they can be inverted, with some advantageeither way. The top terminal with the convex face downward, this beingdone primarily to insure safe interfit of the side notches 62 of the topstrips with the upper edge of the partition 50. Dependstrips 26 and 20preferably are disposed,

able location and holding of the top terminal strips is a labor savingconvenience when applying the cover plate. Depending on the materialused, the cover may be secured to the base by use of a solvent, or acement, or by welding. In the case of nylon it would not be feasible touse any presently available cement. The welding may be performed indifferent known ways, one of which is by means of ultrasonic vibration.The cover is applied under a desired force to place the stacks andterminal strips under a desired preloading pressure. A suitable assemblyfixture may be employed for this purpose.

It will be evident that the four stacks of rectifier cells are disposedin the arms of a conventional electrical bridge of the closed end type,and that the terminal strips act also as jumpers at the corners of thebridge. Alternating current may be applied to either the pair ofbottomterrninals 22, 24, or to the pair of topterminals 26, 20, withappropriate polarity of the selenium cells, and the other pair ofterminals delivers the rectified output. The latter may be obtained ineither polarity, as by turning over all of the stacks of cells. Theelectrical arrangement is symbolized in FIG. 7 in which the four stacksof cells are indicated by the oppositely facing triangles 16, 12, and14, 18, and in which the alternating current is shown applied to theterminal strips 26 and'20, while the direct current is taken from theterminal strips 22 and 24.

If desired the case may be modified to provide a flange which protectsthe soldering lugs. Such an arrangement is shown in FIGS. 5 and 6 inwhich the case 80 has connected flanges 82 and 84 to physically protectthe two pairs of projecting soldering lugs. In other respects theconstruction is the same as that already described. The flanges may bemolded integrally with the case.

The construction shown is inexpensive because of the minimum number ofparts employed. It is also very compact. The rectifier illustrated inFIGS. 1-4 has a case which is only 4 inch by inch. The cells are 0.29inch square, and have a thickness of 0.025 inch, there being four cellsin each stack as here illustrated. The dimensions may be varied, itbeing understood that quantitative values have been given solely by wayof illustration, and are not intended to be in limitation of theinvention.

The number of cells in each stack may be varied, with appropriate changein the height of the case. Even with the same case, the number of cellsmay be varied by changing the thickness of the individual cells.Alternatively, the height of the case may be dimensionedfor say fivecells, and then when only four cells are to be used, a filler piece ofplain metal may be employed in lieu of the fifth cell. i

It is believed that the construction and method of assembly of myimproved flat package bridge rectifier, as well as the advantagesthereof, will be apparent from the foregoing detailed description. Itwill also be apparent that while I have shown and described theinvention in a preferred form, changes may be made without departingfrom the scope of the invention as sought to be defined in the followingclaims. four stacks being arranged in a square means merely that thestacks are arranged two by two, rather than meaning equality ofdimension, although it is preferable and most convenient to employsquare cells so that all four terminal strips may be alike.

I claim:

1. A fiat package bridge rectifier comprising four stacks of imperforaterectifier cells, said stacks being arranged relative to one another in asquare, two pairs of elongated terminal strips, the two strips in eachpair being collateral of one another, one pair being beneath the fourstacks and the other pair being above the four stacks, one pair beingdisposed transversely of theother pair, said assembly of cells andterminal strips forming a bridge of four rectifiers with four terminalstrips for external connections, the terminal strips being made ofresilient metal, and each being concavo convex at each stack, and ahous- In the claims the reference to 4 ing around the stacks andterminal strips, said housing being so dimensioned as to bear againstthe four terminal strips and to load the said terminal strips in orderto apply resilient pressure to the stacks of cells.

2. A flat package bridge rectifier comprising four stacks of rectifiercells, said stacks being arranged relative to one another in a square,two pairs of elongated terminal strips, the two strips in each pairbeing collateral of one another, one pair being beneath the four stacksand the other pair being above the four stacks, one pair being disposedtransversely of the other pair, said assembly of cells and terminalstrips forming a bridge of four recti-l fiers with four terminal stripsfor external connections, a molded insulating case for housing the cellsand terminal strips, said case having a bottom and four edge walls atleast some of which have slots to receive soldering lugs, a firstpartition extending from a first slotted wall to the opposite wall, asecond partition extending from a second slotted wall to the oppositewall, each partition being interrupted at points between the otherpartition and the edge walls, the terminal strips being notched at theside edges to receive the interrupted partitions and each having asoldering lug at one end which passes through one of the slots, thecells being dimensioned to be received within the partitions, and acover disposed over the case and secured thereto and exerting pressureon th strips and stacks.

3. A flat package bridge rectifier comprising four stacks of rectifiercells, said stacks being arranged relative to one another in a square,two pairs of elongated terminal strips, the two strips in each pairbeing collateral of one another, one pair being beneath the four stacksand the other pair being above the four stacks, one pair being disposedtransversely of the other pair, said assembly of cells and terminalstrips forming a bridge of four rectifiers with four terminal strips forexternal connections, a molded plastic case for housing the cells andterminal strips, said case having a bottom and four edge walls, one ofwhich has two full depth slots, and an adjacent one of which has twoshort slots, a first partition extending from th first slotted wall tothe opposite wall, a second partition extending from the second slottedwall to the opposite wall, the second partition being interrupted atfull depth at points between the first partition and each of the edgewalls to which it runs, the bottom terminal strips being notched at theside edges to receive the interrupted partition and having solderinglugs at one end to passthrough the full depth slots, the cells beingdimensioned to be received within the partitions, the top terminalstrips overlying the first partition and having soldering: lugsprojecting through the short slots, and a plastic in-- sulation coverdisposed over the case and secured thereto and exerting pressure on thestrips and stacks.

4. A rectifier as defined in claim 2, in which the ter-- minal stripsare made of resilient metal and are each concavo convex at each stackand in which the terminal strips are loaded by means of the cover toapply resilienti pressure to thestacks of cells.

5. A rectifier as defined in claim 2, in which the partitions near theedge walls have upstanding studs, and in which the partitions have acruciform center and at said cruciform center have a hole, and in whichthe cover has a depending locating stud at its center to fit in saidhole, and has four holes near its periphery to receive the aforesaidstuds.

6. A rectifier as defined in claim 2, in which the cells are square, andin which the partitions forrn compartments and said compartments formedby the partitions for receiving the cells are square, and in which thecase and its cover are square.

7. A rectifier as defined in claim 3, in which the terminal strips aremade of resilient metal and are each concavo convex at each stack and inwhich the terminal strips are loaded by the cover to apply resilientpressure to the. stacks of cells.

8. A rectifier as defined in claim 3, in which the first partition isinterrupted like the second partition but for only a slight depthsufficient to receive the top terminal strips, and in which the latterare notched at the sides like the bottom terminal strips.

9. A rectifier as defined in claim 3, in which the partitions near theedgewalls have upstanding studs, and in which the partitions have acruciform center and at said cruciform center have a hole, and in whichthe cover has a depending locating stud at its center to fit in saidhole, and has four holes near its periphery to receive the aforesaidstuds.

6 References Cited by the Examiner UNITED STATES PATENTS 2,215,6679/1940 Sherman 3172.34 3,211,873 12/1965 Vigren et a1. 200-166 FOREIGNPATENTS 130,847 1/ 1949 Australia.

M. GINSBURG, Assistant Examiner.

1. A FLAT PACKAGE BRIDGE RECTIFIER COMPRISING FOUR STACKS OF IMPERFORATERECTIFIER CELLS, SAID STACKS BEING ARRANGED RELATIVE TO ONE ANOTHER IN ASQUARE, TWO PAIRS OF ELONGATED TERMINAL STRIPS, THE TWO STRIPS IN EACHPAIR BEING COLLATERAL OF ONE ANOTHER, ONE PAIR BEING BENEATH THE FOURSTACKS AND THE OTHER PAIR BEING ABOVE THE FOUR STACKS, ONE PAIR BEINGDISPOSED TRANSVERSELY OF THE OTHER PAIR, SAID ASSEMBLY OF CELLS ANDTERMINAL STRIPS FORMING A BRIDGE OF FOUR RECTIFIERS WITH FOUR TERMINALSTRIPS FOR EXTERNAL CON-